Automatic dipper-trip.



H. I. MELVILLE. AUTOMAT|C DI PPER TRIP. APPLICATION FILED APR. 26. ms.

Patented Mar. 28, 1916.

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H1]. MELVILLE.

AUTOMATIC DIPPER TRIP.

APPLICATION FILED APR. 26. 1915.

1,17?,20%.- Patented Mar. 28,1916.

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INVENTOR HERBERT .'r. MELVILLE, or rirrsnunen, rnnnsvnvamai I AUTOMATIC DIPJPEIt-TRIP.

Specification of Letters Patent. Patented 2%,

' Applicationfiled April 26,1915. Serial No. 23,896.

To all whom it may concern:

Be it known that I, HERBERT J. MELVILLE, a citizen of the United States, residing at Pittsburgh, in the county of Allegheny, State of Pennsylvania, have invented certain new and useful Improvements in Automatic Dipper-Trips, of which the following is a specification.

My invention relatesto devices for automatically tripping the latches on the buckets or dippers of steam shovels, dredges and similar excavating machines or the like.

My improved device comprises an operating cylinder and'a wire ropeconnecting the same with the latch-bar on the bucket, to-

gether with a' rope tensioning device and a three-way cock to control the action of the cylinder.

In present practice .it is usual on steam shovels to operate the trip rope manuallyonsmall one man shovels this causes extra fatigue on the operator as well as loss of time, 'and on large shovels this duty is more onerous on account of the larger bucket. 7

Referring to the drawings Figure ,1 is a diagrammatic side elevation of .a steam shovel equipped with my improved device.

eratin'g cylinder andthe grip. Fig. 3 is a side elevation of the grip. Fig. 4 is an end view (plan) of the grip. Fig. 5 is an edge view of the same. Fig. 6 is a cross section j at , bucket or dip of the tension drumfor the grip rope. Fig. 7 1s aside elevation of the same, and Fig.8 is a diagrammatic 'cross section of the three- Way operating valve.

The shovel 1 is provided with a boom 2 which carries the dipper sticks 3 all of which may be ofany usual or desired construction. The dipper sticks 3 carry the per 4 which is provided with '1 the usual hinged bottom 5 having any desired form of latch (not shown). is pivoted to the lower end of one .ofthe dipper sticks 3 and connected with a short chain? which releases'the latch. "A trip Tops 8 is also fastened to'the' lever erate the same, so, thencethrough the hollow. piston rod of the agroovedidler sheave 2 to the grip 10, and

' operating cylinder 11 to the tension drum 55 an idler sheave jand 7 .9

'12 which is mountedpreferably on a bracket 13 secured to the boom-Y2. If desired however the tension drum112 may be replaced f m h 8 A lever 6 i to opand this rope is carried over' shptvn Fig. 2S0

tended as shown in dotted lines at 8 to the locationshown for the tension drum in dot-' are operated through links 18 and pins 19 and 20 from a crosshead 21. r

The operating cylinder 11 is provided with a front head 22 havingv a gland 23 and packing 24. It'also contains a piston 25 secured to a guide 26 which extends downwardly through the back head 27. A spring 28 keeps the piston 25 normally at the upper end of the cylinder 11 as shown in Fig. 2. A hollow inner piston rod 29 has one end screwed into the piston 25 and the other end screwed into the cross head 21. A hollow outer-piston rod 30 surrounds therod 29, and has itsupper end screwed into the jaw holder 14. The rod 30 passes through the packing 24 and has a flanged end 31 inside the cylinder 11 between head 22 and piston- 25. The grip rope 8 passes between the jaws- 17 and then downwardly and 30, and the guide 26.

inside the rods 29 Steam (or air) is admitted above the pis- I ton through a pipe 32 in which there is placed'a three-way. valve'33 having a plug 34 and L shaped handle 35. To the arm 35 of handle 35- there is fastened a jerk cord 36 which leads to the operator. Tothe arm 35 there is fastened a chain 37 the lower end of which-'is'seoured to a ring bolt 38 at the lower end of the piston guide 26 to'close the valve.

One end of the trip rope 8 is fastened to the lever6 which operates the latch as be.-

fore described, and the" other end is fastened to a drum' 39 which is loosely mounted on afixed pin 40. The drum 39 contains a coiled spring '41, one end of which is fasjtened to the pin'40, and the other tothe drum 39 in a well known manner. The trip rope 8 is wound several times around the drum 39 so as to allow ample length for the v movements of the dipper:-

. The dipper latch hasnot been shown in detail as all steam shovels are provided with a latch o erated by a pull rope. and such a construct on is well known in the art; I

My improved device operates as follows: The grip 10 and cylinder 11 with their contained parts are normally in the position that the'trip rope 8 may valve 33 to its initial position.

move freely to accommodate the dipper, the drum 39 maintaining just sufiicient tension on the rope 8 to take up the slack thereof without affecting the latch. When the dipper is to be dumped the operator jerks the cord 36 which opens the valve 33 and admits pressure to cylinder 11 above piston 25. Piston 25 then starts down drawing with it the inner piston rod 29,

- (which is a loose fit inside rod 30) crosshead 21 and links 18 thus the first effect of the motion is to tighten jaws 17 on rope 8. Rod 30 is frictionally held from motion by packing 24 until crosshead 21 moves down and strikes the upper end of the same, (see initial clearance at 42) or until the jaws 17 close firmly on rope 8. After this the piston 25 moves down against the pressure of spring 28 and tightens the grip rope 8 until it operates the lever 6 and dumps the bucket. Near the end of its downward stroke the guide 26 tightens the chain 37 and resets the Thus one jerk on cord 36 dumps the bucket.

It is not necessary that my device be applied to a shovel or other excavator in the precise manner shown. The cylinder 11 may be set horizontally or inclined and various other modifications may be made by those skilled in the art.

I claim as my invention:

1. Means for applying tension to a rope comprising a cylinder, a piston therein, a hollow piston rod secured to said piston, a gripping device carried by said piston rod, a central opening in said piston, and a central opening in the bottom of said cylinder through'which the rope may pass, whereby all the above parts are grouped concentrically about the rope.

2.-Means for applying tension to a rope comprising a single acting cylinder, a piston therein, a spring opposed to said piston, a

piston rod for said piston, a. sleeve slidably mounted on said piston rod and having a shouldered end Within the cylinder, packing surrounding said sleeve, a cross head on said sleeve, a jaw carrier on said piston rod, jaws for gripping the rope on said jaw carrier, and links connecting said cross head and said jaws whereby relative endwise movement of the piston rod and the sleeve may operate to close the jaws.

3. Means for applying tension to a rope comprising a cylinder, a piston therein, a piston rod for said piston, a sleeve loosely mounted on said piston rod and having a limited endwise motion thereon, a device mounted on the cylinder and contacting with said sleeve for frictionally retarding the same, and a gripping device for the rope comprising a fulcrum member provided with gripping jaws and an operating member having links connecting itself and the jaws to operate the latter, the said fulcrum memher being connected to the sleeve and said operating member to the piston rod, whereby relative motion between the rod and sleeve operate to open or close the jaws.

4. Means for applying tension to a rope comprising a cylinder, a piston therein, a piston rod extending through one end of the cylinder and provided with a gripping device for a rope, a guide secured to said piston and extending through the other end of the cylinder, a pressure controlling valve connected to said cylinder, means for opening said valve to admit pressure to the cylinder, and a connection between said guide and said valve for closing the latter.

In testimony whereof I hereunto aflix my signature in the presence of two Witnesses.

HERBERT J. MELVILLE. Witnesses:

M. T. PERKINS, J. I. KLINE. 

